Yesterday, SpaceX successfully launched its Falcon Heavy rocket to much fanfare. After numerous delays due to upper-level winds, the rocket lifted off at 3:45 PM ET on Tuesday. The rocket worked perfectly, delivering the test payload into orbit (a red Tesla roadster) and coasting for six hours before performing another engine burn to take it deeper into the solar system. SpaceX was even able to land two of the three boosters in beautiful synchronization. The core booster was lost because of low propellant; it slammed into the ocean at around 300 miles per hour, 300 feet from the drone ship.
This is a huge milestone for SpaceX. The question now is: What's next?
There were a lot of expectations pinned on this rocket, if not this specific launch. It would have been disappointing (rather than catastrophic) if the rocket had failed; SpaceX could have attempted another Falcon Heavy launch in a few months, assuming the launch pad survived. It was a test flight, not a make-or-break launch. But it was crucial for what's to come.
With the successful Falcon Heavy maiden voyage, SpaceX has proven that it's capable of lifting massive cargo into orbit. The rocket is, after all, now the biggest and most powerful operational rocket in the world. It's second only to the Saturn V rockets of the Apollo era in terms of lift power to low Earth orbit (though the Space Shuttles had more thrust power at launch).
This means that SpaceX now has a launch vehicle capable of lifting over twice the payload of any other operational rocket. But right now, the Falcon Heavy only has a few additional launches scheduled. Customers include a Saudi Arabian communications satellite, the US Air Force and a test of solar sail technology from The Planetary Society. However, as NASA's own behemoth rocket, the Space Launch System (SLS) continually overruns budgets and is delayed, it's conceivable the organization could turn to SpaceX for its heavy-lift needs. Additionally, now that SpaceX has proved the Falcon Heavy works, it will encourage more customers to book launches.